ExpandableTree<T> constructor Null safety

const ExpandableTree<T>(
  1. {Key? key,
  2. NodeSelectedCallback<T>? onSelect,
  3. Widget closedTwisty = DEFAULT_CLOSED_TWISTY,
  4. Widget openTwisty = DEFAULT_OPENED_TWISTY,
  5. required List<TreeNode<T>> nodes,
  6. required NodeBuilder<T> nodeBuilder,
  7. double childIndent = DEFAULT_CHILD_INDENT,
  8. bool initiallyExpanded = false,
  9. Color? openTwistyColor,
  10. Color? closedTwistyColor,
  11. TwistyPosition twistyPosition = DEFAULT_TWISTY_POSITION,
  12. BoxDecoration? childrenDecoration,
  13. BoxDecoration? submenuDecoration,
  14. EdgeInsets? submenuMargin,
  15. EdgeInsets? childrenMargin,
  16. Color? submenuClosedColor,
  17. Color? submenuOpenColor}
)

Default constructor. Used for the root as well as any sub-nodes that can be expanded to show children

Implementation

const ExpandableTree({
  Key? key,
  this.onSelect,
  this.closedTwisty = DEFAULT_CLOSED_TWISTY,
  this.openTwisty = DEFAULT_OPENED_TWISTY,
  required this.nodes,
  required this.nodeBuilder,
  this.childIndent = DEFAULT_CHILD_INDENT,
  this.initiallyExpanded = false,
  this.openTwistyColor,
  this.closedTwistyColor,
  this.twistyPosition = DEFAULT_TWISTY_POSITION,
  this.childrenDecoration,
  this.submenuDecoration,
  this.submenuMargin,
  this.childrenMargin,
  this.submenuClosedColor,
  this.submenuOpenColor,
}) : super(key: key);